The deer mouse, Peromyscus maniculatus, is a common rodent found throughout much of North America, including Utah. One reason that this small brown mouse is so common is that it can thrive in a variety of habitats, ranging from deserts to grasslands to coniferous forests.

The deer mouse eats a variety of foods, including small invertebrates, seeds, and other plant material. Deer mice can produce several litters each year. Gestation lasts approximately three weeks, and young become independent two to three weeks after birth. Average litter size is five.

This otherwise nondescript rodent gained a great deal of notoriety in the early 1990s when it was linked to hantavirus, a virus which can create pulmonary problems in humans, sometimes leading to death. Because of the risk of hantavirus infection, extra care should be taken when in contact deer mice or deer mice feces.